Liquid dispensers are well known and are in substantial commercial use. Such dispensers are utilized to deliver viscous liquids such as liquid soaps, hand lotion, creams and the like. Key requirements for such dispensers are delivery of metered amounts of product upon actuation of the dispenser without leakage from the dispensing tube, prevention of contamination, reduction in the difficulty in cleaning or replacing the liquid container, and eliminating entrapment of air and other undesirable features.
In prior dispensers, the viscous liquid is supplied and held within the dispenser in a variety of ways. For example, in some dispensers, it is necessary to pour bulk soap into the dispenser directly, while in other dispensers a bag of liquid to be dispensed is hung from hooks or pins within the dispenser. In other dispensers, a reservoir or bag of liquid material such as soap is provided in an outer casing such as a cardboard box container which is placed upon a support structure within the dispenser.
A variety of such dispensers have been disclosed in various U.S. patents. For example, McDermott, et al., U.S. Pat. No. 4,667,854, discloses a liquid dispenser such as a liquid hand soap dispenser which utilizes a collapsible reservoir or bag for the liquid within the dispenser housing, in which the collapsible bag is contained within an outer casing such as a cardboard box to provide support for the collapsible bag. In Roggenburg, Jr., et al., U.S. Pat. No. 4,570,827, a liquid dispenser is disclosed which includes a flexible bag which is formed with two chambers, a supply chamber and a discharge chamber, and the bag is suspended in the housing of the dispenser from projecting pins. Christine, U.S. Pat. No. 4,349,133, discloses a dispenser that includes a housing in which is mounted a disposable container holding liquid materials, in which the container is of accordion-type construction and is placed directly within the housing on support elements or shelves attached to the housing.
Other examples of prior dispensers include Tucker, et al., U.S. Pat. No. 4,238,056, which discloses a soap dispenser having a soap reservoir comprising a sump and a container, in which the reservoir container is supported inverted on the reservoir sump emptying downwardly therein, and the container is preferably a plastic bottle of a particular configuration to be positioned within the dispenser cabinet in an inverted position. In Pliml, Jr., et al., U.S. Pat. No. 3,881,641, a dispensing device is disclosed for discharging a quantity of flowable material such as food condiments, which includes a plastic bag containing the material to be dispensed, with the bag hung from a support hook located on a wall panel forming part of the structure of the dispensing apparatus. Asplund, U.S. Pat. No. 3,870,201, discloses an apparatus for dispensing a paste product comprising a container with an elastic outlet tube, a casing surrounding the container and a push means for acting on the outlet tube for pressing out the product from the container.
The above patents disclose various dispensers which house bags or containers for viscous materials such as liquid soap and various mechanisms for supporting the bags within the dispenser. However, prior dispensers have exhibited one or more disadvantages such as difficulty in replacing the liquid reservoir, liquid dripping, opportunity for bacterial contamination, the handle pulling action serving to pull the dispenser from the mounting, potential for entrapping air, etc. Also, use of small disposable boxes in housing a collapsible reservoir or bag such as disclosed in U.S. Pat. No. 4,667,854 increases the waste material to be disposed of once the reservoir is depleted of its contents since both the box and reservoir are discarded.
Therefore, there is a need for an improved dispenser having a reservoir or bag holder which overcomes the above disadvantages. Various objects and advantages of the invention will become apparent from the following description thereof.